This study represents a continuous effort to develop and establish the most reliable and reproducible method for culturing cerebromicrovascular endothelium derived from SJL mice susceptible to experimental allergic encephalomyelitis. The focus of this investigation has been to analyze the nutritional requirements needed for sustained long-term growth and propagation of the endothelium. High concentration of endothelial cells grow equally well in medium containing 10-20% fetal calf serum (FCS). They required endothelial cell growth factor (ECGF) for maximal proliferation. Inclusion of heparin synergistically increased the proliferative response of the cells. In the presence of high concentration (20%) of FCS, heparin surpassed ECGF in the ability to support increased proliferation of the endothelium. A more detailed analysis of various nutrients is still required for establishment and characterization of long-term endothelial culture for expediting the investigation concerned with the interaction between capillary endothelium and immune cells. This investigation was interrupted during the reporting period because of fire destruction of the SJL mouse breeding facilities.